Use your NLE.

Several things to consider that come to mind:

VIDEO
Is it safe to assume these are consumer-grade, or "pro-sumer" cameras without any timecode, or genlock capability?

You will be surprised how much events will drift when you take footage from 2 or more cameras and try to A-B(-C-D) roll them. You may also be surprised how inaccurate 30 frames per second is compared to audio - which even on the worst resolution audio editing software is the video equivalent of 44,100 fps. (BTW - shoot your video using 48k audio) The prolbems with relatively coarse 30fps, will manifest itself in numerous ways "lining up" multiple cameras. Without any way to framelock the free-running cameras can be off by half a frame, before they start to drift.

If you're using tape, here's a tip that may help slightly dealing with the drift: If Tape A was shot on Camera #1, use Camera #1 to play Tape A as you capture it into your computer. If Tape B was shot on Camera #2, use Camera #2 to capture Tape B, and so on. This will at least improve your chances that the duration of the clip will match the slight mechanical variation in speed from camera to camera. If you're shooting to DVD or SD cards - it's not a factor. In that case, it's already digitized and you're at the mercy of the internal clock accuracy of each device (which will vary slightly), hopefully it's not enough to drift too much too quickly.

And to your last question, most top-notch editors such as Final Cut Pro & Premiere are not set-up to A-B roll (let you to view all the clips at once). They will let you put all the clips on a timeline and line them up, but you can only see the Track A that is on top. To view any track below (Track B), you have to cut Track A out of the way. When you see someone doing that multiple monitor thing they are using a very expensive combination of hardware and software all synchronized to SMPTE timecode both when it was shot - and as it's playing back.

AUDIO
If you're relying solely on a feed from the FOH mixer identical to the room mix - you may be very disappointed. Often times, that ends up with an 'upside-down' mix. If it's in a large neutral venue, it can work beautifully. But if it's in a smaller venue where, for example, the bass amp is filling the room without much help from the PA system - the soundperson will have the bass off or nearly off in the mix - because they are filling the room with stage-volume. The resulting board mix will have little or no bass in it. As you extrapolate that out over a whole band the things most present in the room will be the things most lacking on the board recording. In my opinion, it would be better to take an Aux feed from the mixer if available (even if it's mono) and have someone try to monitor it with headphones and make a mix that works. And I'd recommend you add at least one room mic that is routed to your Aux mix for video - without being sent to the FOH speakers. The room mic lets you capture audience response and a more natural feel to the recording. You may have to gradually turn that mic up as the song finishes to get the crowd reaction, then back it down to the ambient room mic level during the next song. Again, if it's not a band situation - some of those things may be less of a concern for you. But not having much detail, I can only guess based on similar questions I've seen before.

There's so much more to this, but I gotta run - hopefully this will give you some food for thought and you can correct me if I've assumed anything that isn't true. I'll check back later, and maybe some of the others who have some experience in this department can add to the conversation while I'm gone.

Best of luck.

You have a few options here. Firstly, having produced lots of music entertainment videos, when you are shooting with multiple cameras and you need to see all 4 cameras, you generally have no choice but to put out 4 independent television monitors. Conversely, with a large flat-panel display, you can purchase a " Quad splitter ". This device will allow the input from all four cameras. It will then split them to appear as 4 Independent pictures on a single large flatscreen LCD.

Conversely, once you have shot with all four simultaneous cameras, you'll then " injest " them into the computer. Because of the crystal controlled clocking in all of these camcorders, they will generally hold perfect synchronization without much difficulty. Back in the old film days, we would refer to this as " Crystal synchronization ". But with today's technology, it's already built into every camcorder.

Numerous programs such as Sony Vegas allow for multi-camera operation. You will select in the drop-down menus "multicam" and enable a multicam track. This will then show all 4 cameras within the timeline. But this is not possible in real time. It's after you have shot the show. This will then give you the opportunity to synchronize all 4 camera shots to be in perfect synchronization. Then all you need to do is click on each one of the 4 windows to select the shot you want to be viewing at the time. It's kind of like pushing buttons on an actual video switcher. Otherwise, you may need to purchase a video switcher if you are intending to produce this for live broadcast?

Since most of these camcorders offer real-time composite video outputs, you would have to have cables running from each one of the camcorders 100% of the time, to external television monitors. But let's be real, you really can't be playing in a band while trying to pay attention to 4 separate television monitors strewn throughout a room. You would just have to let your camera guys do their thing and communicate with each other in some manner fashion or form. Everybody has their limits and it sounds like you are exceeding yours.

Musical video producer here
Mx. Remy Ann David

Woah, it's not just me.

Strangely enough, most consumer camcorders don't need to have SMPTE nor genlock to remain perfectly in sync over long periods of time. Having some kind of time code is more important for longform documentary/feature video productions than contiguously running camcorders for music entertainment. You will also be dealing more with 48 kHz audio than 44.1 kHz audio since the timing of 44.1 kHz audio does not perfectly synchronized mathematically with 48 kHz audio. This is an important factor when dealing with video productions. So when I'm recording 24 track digital for a production involving video, I'm always recording at 48 kHz to achieve that perfect synchronization with the video that is also based upon 48 kHz such as you find on DVDs which ain't 44.1 kHz and none of them are. So in the transcoding process, yup, you'll experience drift when dealing with 44.1 kHz audio in video production. Thankfully, you can still make it acceptable 44.1 kHz downsample, transcoding for CD release without the video. And while they'll be some timing discrepancies, there won't be any picture on a CD release to conflict with lip-synch with video.

One should always also keep in mind that if one is using an ALESIS HD 24, their sample rate is only accurate and 48 kHz because 44.1 kHz isn't exactly 44.1 kHz. It's off by .002 or is that .003? Something like that but it causes its problems nevertheless. That problem can be remedied for the HD 24 with the utilization of an external master clock set precisely at 44.1 kHz. This will then force the machine to record at precisely 44.1 kHz so that when you dump it into your computer & software, the piano won't appear out of tune if it is to be overdubbed or corrected in any way. It doesn't matter about the other instruments since they are so easily tuned and can tune to the slightly off sample rate playback from the computer which is actually accurate but the initial recording isn't. So it will play back at the proper sample rate within the computer slightly off pitch because it's not an accurate 44.1 kHz on HD 24 by ALESIS. And since I love mixing in analog on the Neve, I'm generally recording 48 kHz on the ALESIS HD 24 XR, anyhow. Then mixing down to my MOTU 2408 MK I I at 44.1 kHz is straight up accurate and so no problems there. Though it does become a little dicey when working strictly ITB and having to deal with that discrepancy with the HD 24's variation on 44.1 kHz without an external master clock (which I don't have). Although I can clock the HD 24 from the accurate 44.1 kHz clocking output from the MOTU 2408. That clock does not have the extreme accuracy and low jitter of a Big Ben or other master clocks. No matter, it's all the same junk to me and that 44.1 kHz clock from the 2408 is at least accurate at 44.1 kHz. Jitter is just the digital equivalent to the analog flutter we always had to deal with with analog recorders. So big deal. Get over it. It's digital flutter. It's just that it's such a fast flutter, it has been coined " jitter ". And since I'm in analog guy that dates back to the early 1970s, a little flutter or a little jitter is good for the soul. I'm really not into this digital blah blah when it comes to this kind of minutia. It really doesn't affect the superiority of my skills. People don't listen to the specifications of the equipment. They listen to the performance of what's recorded and for the most part, most people wouldn't know that they were hearing some jitter if they fell over it. To me talking about jitter was like being back in the late 1970s when the manufacturers wanted to stop spending all that money on Transformers and began touting how superior transformer less circuits specked out. BFD they're not superior. They're just cheaper to implement. So Chevrolet is really like a Cadillac since they both have interchangeable GM parts. And both get you from point A to point B with the same mpg's and their factory supplied Delco radios. This is just typical technical shoptalk that we all love to expound about when talking about minutia improvements in equipment. It's really part of the audio passion and the audio bug that we all just eat up.

I've never tried chocolate covered grasshoppers
Mx. Remy Ann David

Use a strobe once in a while (a flash photo between songs, for instance) to help line up the video. Just find that frame on all the angles and line them up on the timeline. Lining one flash up and comparing how the next flash lines up will give you an idea of how much drift you're getting. I doubt it will be much over a song.

Record your audio in 48k. It's just how you do film and video.